The mission of the Animal Resources Facility is to enable Burnham Institute Cancer Center investigators to use small animals for biomedical research, a mission that has been and will continue to be critical to the success of the Cancer Center. The Facility operates as a centralized service in which most procedures are performed by trained Facility staff. This ensures a consistent standard of care, minimizes traffic through the Facility, and frees Cancer Center investigators from having to hire and train their own personnel for these tasks. The Facility provides three types of services: Mouse Genetics, Husbandry, and In Vivo Analysis. Mouse Genetics creates new lines of transgenic and gene knockout mice, Husbandry maintains and manages existing colonies of animals, and In Vivo Analysis helps to characterize the phenotypes of animals used for experimental studies. Current and projected cancer-related projects supported by the In Vivo Analysis service include the use of xenograft and transgenic mouse models to study mechanisms of tumor induction and progression, along with testing the efficacy of new agents for slowing tumor growth and metastasis. It is envisioned that the Center's Drug Discovery Initiative will lead to the identification of new compounds that will need to be tested in vivo for activity against tumor growth and metastasis. To aid in the evaluation of these drugs, the In Vivo Analysis service will offer a centralized Tumor Analysis Core to establish and evaluate tumor onset and progression in transgenic and xenograft models. Specific Aims for this core will be to: 1) Offer consultation and information about the use of animal models, drug formulation, and drug administration; 2) Maintain two transgenic mouse colonies, TRAMP and MMTV-PyMT, for the respective study of prostate and mammary cancer. De novo tumorigenesis in these lines closely mimics that seen in human cases; 3) Maintain nude mice and stocks of MDA-MB-435 breast cancer and PC-3 prostate cancer cell lines for xenograft studies of drug effectiveness against human mammary and prostate tumors, respectively; 4) Initiate tumor growth (by breeding or xenografting) and quantify tumor onset, growth, and metastasis in control and treated animals and ; 5) Collaborate with Informatics and Data Management Resources to maintain data archives for comparison of different drug trials.